1. Field of the Invention
The present invention relates to a movable contactor of a circuit breaker, and more particularly, to a movable contactor of a circuit breaker which can minimize manufacturing cost and to a fabrication method for finger thereof.
2. Description of the Background Art
In general, a circuit breaker is connected to a circuit that a current flows to make the current flow in the circuit in normal state. And, when a fault current (or abnormal current) occurs in the circuit, the circuit breaker breaks the fault current, thereby protecting the circuit and its device.
Such circuit breakers include a casing having a receiving space therein, a plurality of fixed contactors having a fixed contact and fixed inside the casing, a plurality of movable contactors having a movable contact formed to contact the fixed contact and disposed inside the casing so as to perform a relative motion with respect to the fixed contactor, a driving unit for driving the movable contactors, and a detecting unit for detecting overcurrent, a fault current, etc. and for driving the driving unit.
One side of the movable contactor is connected to outlet-side fixed contacts of the fixed contactor, and another side of the movable contactor is connected to or separated from inlet-side fixed contacts of the fixed contactor according to a movement of the movable contactor.
And, a plurality of arc extinguishing rooms are disposed above the movable contactor so as to exhaust the arc generated when the movable contactor contacts or is separated from the fixed contactor.
Such circuit breakers are operated as follows:
First, in normal state, the movable contactor is connected to the inlet-side fixed contact of the fixed contactor. Then, a power is supplied through the inlet-side fixed contacts of the fixed contactor, and flows in an internal path of the movable contactor. The power flowing in the internal path of the movable contactor flows to a load unit through the outlet-side fixed contacts of the fixed contactor.
And, if the detecting unit detects overcurrent and a fault current, the driving unit is driven by an internal operation mechanism. While the movable contactors angularly rotate according to the driving unit's motion, the movable contacts of the movable contactors and the inlet-side fixed contacts of the fixed contactors are separated from each other, thereby breaking the current's flow.
The movable contactor includes a plurality of fingers for contacting or being separated from the inlet-side fixed contacts of the fixed contactor, and lead wires each coupled to an end of each of the fingers and connected to the outlet-side fixed contacts of the fixed contactor so as to apply the current flowing to the fingers to the load unit.
Meanwhile, the finger of the movable contactor may be formed of an expensive copper material having excellent conductivity and processability.
Accordingly, to reduce the manufacturing cost of the movable contactor, minimization of the material loss is the major issue when fabricating the fingers.